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Flat orange ribbon cable with connectors at each end

DELL

DELL Inspiron 5421 3421 5437 3437 Latitude 3440 Ribbon Cable 31P3J NJT90 accessory

SKU CH-K1F3-X67AB

Genuine Dell OEM ribbon cable connecting the USB/SD card I/O board to the motherboard for Inspiron 14R 5421, 3421, 5437, 3437 and Latitude 3440 laptops

  • Genuine Dell OEM part ensures exact fit
  • Connects USB and SD card board to motherboard
  • Compatible with Inspiron 3421, 5421, 3437, 5437 models
  • Works with Latitude 3440 laptops
  • Part numbers 31P3J and NJT90 match original

Genuine Dell OEM ribbon cable for Inspiron

This genuine Dell OEM ribbon cable connects the USB/SD card I/O board to the motherboard in compatible laptops. It fits Inspiron 3421, 5421, 3437, 5437 and Latitude 3440 systems. The part replaces Dell numbers 31P3J and NJT90. Buyers needing a different board connector or a longer flex will not find a match here.

Fits inside the chassis as a direct board-to-board

The cable sits between the I/O board and the mainboard, requiring no extra brackets or adapters. It restores USB and SD card functionality when the original flex is damaged. Installers must open the base cover and route the flex through the existing retention clips. Builders working on non-listed 14-inch models cannot use this part.

Cable only — no screws.

The package contains the ribbon cable exactly as pictured, with no mounting hardware or driver media. Re-use the original screws and latches from the laptop during reassembly. No firmware update or configuration utility is supplied or required. Shops looking for a complete I/O board assembly will need a separate part.

Highlights

  • Genuine Dell OEM part ensures exact fit
  • Connects USB and SD card board to motherboard
  • Compatible with Inspiron 3421, 5421, 3437, 5437 models
  • Works with Latitude 3440 laptops
  • Part numbers 31P3J and NJT90 match original

Specifications

BrandDell

Questions about this item

What part number identifies the ribbon cable that links the USB/SD IO board to the motherboard?

The Dell part number is 31P3J and the alternate number is NJT90.

Does the cable generate noticeable heat or noise during continuous laptop operation?

No, a passive ribbon cable produces no heat or noise of its own.

Which Dell laptops must the buyer already own for this cable to fit?

Compatible models are Inspiron 3421, 5421, 3437, 5437 and Latitude 3440.

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